Lufthansa Flight Training is offering Refresher Training (at a price) contact this guy directly:
[email protected] There are other TRTOīs in Germany offering A300-600 refresher courses:
FSB Flugschule Berlin - International Flight School Berlin
TFC
Cockpit4u - Aviation Service - Berlin I canīt comment on the quality for Cockpit 4u but have worked over the years as instructor A310 for the others and they are good.
Good Luck!